European stocks swung lower amid significant doubts that the region's rescue fund would be strengthened and as the head of the European Central Bank warned that the sovereign debt crisis threatened global economic stability.
Britain's FTSE 100 lost 0.9 per cent, while France's CAC 40 dipped 0.7 per cent and Germany's DAX slid 0.8 per cent.
U.S. stock futures indicated a soft opening as well. Dow futures slipped 0.3 per cent, or 37 points, to 11,331, while S&P 500 futures fell 0.5 per cent, or 5.4 points, to 1,185.50.
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European Central Bank President Jean-Claude Trichet, who is also chairman of the European Systemic Risk Board, said "the high interconnectedness in the EU financial system has led to a rapidly rising risk of significant contagion."
Meanwhile, the fate of the euro zone's expanded rescue fund hung in the balance in Slovakia's parliament, where it needed to be ratified and faced considerable opposition. All 17 countries that use the euro must approve the plan. Sixteen have, and Slovakia votes on Tuesday.
In Athens, inspectors from the European Commission, the European Central Bank and the International Monetary Fund were due to issue a statement after completing an extended review of Greece's tortured progress on its bailout programme.
Greece's bondholders may have to settle for a cut of more than 60 per cent in what Athens owes them, said the head of the euro zone's finance ministers, Jean-Claude Juncker. Many investors believe Greece's debt situation is untenable, even with more reforms and austerity measures.
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Asian markets were still riding Monday's optimism, when the Dow ended more than 300 points higher. Japan's Nikkei rose 2 per cent, Hong Kong's Hang Seng shot up 2.4 per cent and South Korea's Kospi rose 1.6 per cent.
Equities investors are also awaiting the start of earnings season this week, with Alcoa reporting after the market closes Tuesday.
Aluminium slipped to $2,235 (U.S.) a tonne, while copper on the London Metal Exchange fell to $7,268 a tonne.
Benchmark oil slipped 85 cents to $84.57.
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Gold declined 0.5 per cent to $1,663.30 an ounce.
The Canadian dollar traded at 97.16 U.S. cents.